Power-driven hand sheet metal shears



Apnl 21, 1953 R. w. JAMES 2,535,335 7 POWER-DRIVEN HAND SHEET METAL SHEARS Filed April 4, 1949 2 SHEETS-SHEET 1 I J ////A IN V EN TOR.

ROBERT w. JAM 55 A TTORNE Y.

April 21, 1953 R. w. JAMES 2,635,335

POWER-DRIVEN HAND SHEET METAL SHEARS Filed April 4, 1949 2 SHEETSSHEET 2 l I I l I E I l I l I I I i 5 mmmnm I) 7 INVENTOR.

ROBERT W. JAM ES ATTORNEY.

per element. l

Patented Apr. 21, 1953 POWER-DRIVEN HAND SHEET METAL SHEARS Robert W. James, Wichita, Kans.

Application April 4, 1949, Serial No. 85,330

3 Claims.

My invention relates to an improvement in power driven hand sheet metal clippers. An object of. my invention is to provide a tool of the kind mentioned that may be demountably mounted in a chuck of any standard type of hand drill motor which will furnish the power to operate the clipper and the drill motor may be held in the workmans hand and the clipper thereby be guided to clip or cut the sheet of metal along any predetermined line.

A further object of the invention is to provide a tool of the kind mentioned that while cutting the sheet of metal will allow the sheets of metal on both sides of the point of cutting to lie close to, or rest on the table top or surface on which the sheet is lying. This is a feature of importance since it makes'for more accuracy of cutting as well as amplifying the handling of the material during the operation of cutting.

A still further object of the invention is to provide a device of the kind mentioned that is inexpensive, compact, light in weight and therefore easy to handle and use. These and other objects will be more fully explained as this description progresses.

Now referring to the accompanying drawings in which similar numerals of reference designate the same parts throughout the several figures of the drawings:

Fig. 1 is a side view of the clipper and is shown with the clipper being held in the chuck of a drill motor.

' Fig. 2 is a vertical longitudinal sectional view of the clipper and having parts broken away for convenience of illustration.

Fig. 3'is a detail cross sectional view of the clipper, the view being as seen from the line IH-III in Fig. 2 and looking in the direction of the arrows.

Fig. 4 is a rear view of the clipper, the view being as seen from the line IVIV in-Fig. 2 and VIVI in Fig. 7, and looking in the direction of the arrows.

Fig. 7 is a side view of the stationary clipper element.

Fig. 8 is a top plan view of the rockable cutter element, the view being as seen from the line *VII-VIII in Fig. 9 and looking in the direction of the arrows.

Fig. 9 is a detail side view of the rockable clip- Fig. 10 is a front view of the front portion of the clipper device.

In the drawings the device is shown as having a hollow paraboloid shaped body portion that is divided into two halves I 5 and l 6 that are rigidly held together by means of cap screws "and 18 that slidably pass through inwardly projecting boss or ear-like elements in one of the paraboloid halves l6 and are threaded into corre-.

sponding boss or ear-like elements l9 and 2D in the other paraboloid half [5 to form the paraboloid housing I5l6.

Positioned within the apex portion of the paraboloid and between the two halves l5 and [6 thereof is a combination lever guide plate and shear'blade element which consists of a guide plate 21 that convergingly curves to mergeinto a shear blade supporting leg formation 22 the lower end of which is bent side ways and then projects forwardly to form a shear blade 23 having a straight shear edge 24 that is positioned a spaced distance 25 away from the adjacent surface of the guide plate 2|.

The machine is provided with an integrally formed rockable shear blade 26 having a shear edge 2% thereon and operating lever 21 therefor. The inner end of the operating lever 21 has a ball formation 28 integrally formed thereon for purposes that will later be made obvious.

The plate and leg element 2I--22 is provided with a hole 29 that is located about midway the depth of the leg 22 substantially. at the point where the edge curves of the guide plate 2| merge into the formation of the leg 22. The wall bounding the hole 29 is threaded to receive a pivot bolt as will later be described.

The shear blade and operating lever element 26-2T is also provided with a hole 30 therethrough at a point located substantially where the lever portion 21 merges into the shear blade formation 26.

A pivot bolt 3! is slidably passed through the hole 30 in the shear blade and lever element 26-45 and is threaded into the hole 29 in the leg and guide plate 222l to slidably hold the lever element 2'! against the adjacent face of the guide plate 2! with the end of the lever 2] and ball 28 thereon projecting beyond the rear edge Zia of the plate 2!, there being a lock nut 32 threaded on the pivot bolt 3| to lock the pivot bolt 3| in its adjusted position as will be readily understood. The corners of the rear end of the guide plate 21 are provided with a hole therethrough, such as at 33 which, when the plate 2| is placed between the housing halves l5 and [6, will register with the holes through the. loss element l9 and 20 of the housing elements I5 and 16.

The rear portion of the paraboloid housing l5-l 6 is provided with an internal annular channel 34 in which is seated two spaced apart antifriction bearing assemblages 35 and 3B in which is revolvably carried a shaft 31 the rear end of which is reduced in diameter and projects rear- 3 wardly from the paraboloid housing as a drive pin 37a. The other end of the shaft 37 is provided with a disk 38 that is rigidly fixed, or preferablyintegrallxr formed thereon .and is revolvablegsin :close proximity to, :01 against the rear end of the guide plate 2!.

The front face of the disk 36 has an eccentrically positioned groove 39 therein relative to the center axis of the shaft 31. "'Inithe-groove .3.9 is revolvably positioned a ball bearing assemblage 40 in which is seated the ball 28 on the end .of the lever arm 27.

A sleeve 4| is snugly fit on theshaftitlcrandis positioned between the inner races of thebearing assemblage 35 and 36 .and serves as a spacer therefor. The sleeve M is rigidly fixed on the :shaft QT -by'means -ofra- 'setscrew 62 "that is threaded through the sleeve 4 l' and bears against the shaft 37.

Thedrive'pin 37a is receivable inthe chuck '63 "ofa power unit,-preferably an electricdrill motor "'44.

The-paraboloid housing is provided with :a combination 'stabilizenand guide element A that is pivotally attached to therear end of the parapowerunit id is held in'the hand of the workman, the tongue 45 may be-solidly held in its *position againstthe -power'unit 4 i to assist in the stabilization of the paraboloid housing i S and shear during the operation of cutting.

When'the deviceis not in use and is removed ffrom the chuck 13 the'stabilizer-A may be rocked to its folded position against the paraboloid housing 15-1 E as shown in Fig. 5.

To prepare the device for' use the stabilizer maybe turned toits rearward position where- 'upon the drivepin37a may be inserted in the jChuCk'43 ahdthestabilizer leg-'45 resting on the power 'unit it-as" shown in-Fig. 1, whereupon the chuckflfi maybe tightened on the pin 37a and the device is-ready for use.

As the-povver-unit revolves the chuck43, the

' pin't'ia, shaft-'37 and disk 38 is revolved whereupon' the eccentricgroovei isrevo-lved and imparts a-reciprocatory or rocking motion to the lever -27-andthe shear blade -25- which shears against the edge of the shear blade23 so 'thatas a" piece of sheet material is placed between the two shear-blades 23 and 26, the sheet materialwill be out in repeatedstrokesasthe-workman moves the device along.

- Due to the particular design and relative positioning of the blades 23 and 25 and their supports it-is easy te-guide the cutter along any straight or irregular linealong which the object is to be'cut.

Whilethe device asshown and described is probably the preferred'form of the device, it is to-be understood that such modifications of the device may be employed as lie within the scope of theappended claims withoutdeparting from the spirit-and intention-of the inventor. Now having fully'shown-and described my invention, what I olaimis:

1. In a powerdriven hand sheet metal shear device lofetheskind:"described; said device comadvance ;of the =support; and ;in ;:a plane spaced away from and parallel to the support, a hollow handle, a one piece shear blade and rocking lever therefor, said shear blade and rocking lever being 1 pivota'lly carriedon said support, the shearing 1 0- posed forwardly of said support and in shearing edge of said last named shear blade being disrelationto the shearing edge of the first said :shearblade and secured to said support in a position to hold shearing edges of the two shear blades inshearing relation one against the other,

ried in the hollow of .said'handle; saididisk being positioned within- J the hollow of l the handle-and immediately adjacent the rear end of *the:said shearl biade vsupportjtherear eud of: the shear blade rocking ii leveri'being.*positionedi-in isaidl eccentric :positioned .groove, :whereby "the revolving eccentric movement of'ithe groovezwillimpart a rocking movement'tozthe shearblade-androckingarmto-rock the cutting edge of said last mention'ed shearblade.

2. In apower drivenshear device,.theacombination as defined 'in'claim 1, said combination being further characterized by thearear :endso'f *said rocking lever having an anti 'frictiori'bearing thereon that is operab'lein the said eccentrically positionedgroove forease of operating'thedevice.

In a power driven shear device; the combi- I "nationasdefined in claim 1;the rear end of said drive shaft projecting from 'therearof the said handle and being receivable in a rotatablechuck of a power driving unit, a combinationguard and stabilizer and' han'dle extension 'elementpsaid combinationguard and stabilizer-and handleextension element extending partially around the rear portion of the handle element and extending therefrom to, and engageably resting on; thexpowerunit to-stabilize theshear device relative to the power unit, said combination guard and stabilizer and handle extension being pivotally carriedon axially aligned pivotal mountings carried bythe said handle, the center axis of thealigned pivotal mountings intersecting the center axis of the drive shaft and handle of the device; saidhandle extension being'ro'ckable over the end of the drive shaft to a position against the oppositepar-t of the handle for compacting the device forcstorage and transportation purposes. 7 V j ROBERT W. *JAMES. 

